With rapid development of display techniques, the touch display device has been widely applied in peoples' life. At the original stage of development of touch display, a touch display panel is formed by fitting a touch panel and a display panel together, so as to achieve touch display. The touch panel and the display panel need to be prepared separately, the cost is high, the thickness is large, and the production efficiency is poor. With development of the touch display techniques, an embed touch display panel is proposed. The embed touch display panel is formed by embedding a touch electrode into a display panel, which can reduce the thickness of the entire module and can significantly reduce manufacture cost of the touch display device, thereby obtaining attentions of many panel manufactures.
At present, in a touch display panel, a touch signal line and a touch electrode are generally arranged on an array substrate. The array substrate includes: a plurality of parallel scan lines and a plurality of parallel data lines, the scan lines and the data lines are mutually insulated and arranged by intersecting, so as to define a plurality of pixels. Each pixel is provided with a thin film transistor and a pixel electrode, the pixel electrode is connected with a corresponding data line through the thin film transistor in the pixel. Further, in order to achieve touch function, the array substrate further includes a common electrode layer which is not in the layer where the pixel electrode is located, and a plurality of touch signal lines. The common electrode layer is divided into a plurality of common electrode blocks. The common electrode blocks are also used as touch electrodes, the touch signal lines are connected with corresponding touch electrodes.
In the touch display panel, the coupling capacitance between the data line and the pixel electrode is large, especially in a negative liquid crystal display panel, the drive voltage on the date line is high, the voltage has big fluctuation, which results in big influence to the pixel electrode, thus the crosstalk phenomenon of the display device is serious. Generally, since the intervening layer (e.g., passivation layer and/or planarization layer) between the pixel electrode and the drain electrode is thick, so that the depth of the through hole connecting the pixel electrode and the drain electrode is great. Therefore, if directly reducing the width of the drain electrode to increase the distance between the data line and the pixel electrode, when the pixel electrode is connected with the drain electrode through the through hole, problems of wire breakage and fall-off of the pixel electrode may occur, resulting in poor display effect such as dark spots, thereby causing a decreasing yield of the display device.